ZA200409738B - Composition and process for warm compaction of stainless steel powders - Google Patents
Composition and process for warm compaction of stainless steel powders Download PDFInfo
- Publication number
- ZA200409738B ZA200409738B ZA200409738A ZA200409738A ZA200409738B ZA 200409738 B ZA200409738 B ZA 200409738B ZA 200409738 A ZA200409738 A ZA 200409738A ZA 200409738 A ZA200409738 A ZA 200409738A ZA 200409738 B ZA200409738 B ZA 200409738B
- Authority
- ZA
- South Africa
- Prior art keywords
- lubricant
- weight
- composition according
- compaction
- steel powder
- Prior art date
Links
- 239000000843 powder Substances 0.000 title claims abstract description 61
- 238000005056 compaction Methods 0.000 title claims abstract description 45
- 239000000203 mixture Substances 0.000 title claims abstract description 37
- 229910001220 stainless steel Inorganic materials 0.000 title claims abstract description 20
- 239000010935 stainless steel Substances 0.000 title claims abstract description 19
- 238000000034 method Methods 0.000 title description 11
- 230000008569 process Effects 0.000 title description 9
- 239000000314 lubricant Substances 0.000 claims abstract description 37
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims abstract description 10
- 239000011651 chromium Substances 0.000 claims abstract description 5
- 239000012535 impurity Substances 0.000 claims abstract description 5
- 229910052742 iron Inorganic materials 0.000 claims abstract description 5
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims abstract description 4
- 229910052804 chromium Inorganic materials 0.000 claims abstract description 4
- 238000005275 alloying Methods 0.000 claims abstract 2
- 229910000831 Steel Inorganic materials 0.000 claims description 13
- 239000010959 steel Substances 0.000 claims description 13
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 10
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 8
- 150000001875 compounds Chemical class 0.000 claims description 8
- 229910052760 oxygen Inorganic materials 0.000 claims description 8
- 239000001301 oxygen Substances 0.000 claims description 8
- 239000010955 niobium Substances 0.000 claims description 6
- 229910052710 silicon Inorganic materials 0.000 claims description 6
- 239000010703 silicon Substances 0.000 claims description 6
- 150000001408 amides Chemical class 0.000 claims description 5
- 229910052759 nickel Inorganic materials 0.000 claims description 5
- ZOKXTWBITQBERF-UHFFFAOYSA-N Molybdenum Chemical compound [Mo] ZOKXTWBITQBERF-UHFFFAOYSA-N 0.000 claims description 4
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 claims description 4
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 claims description 4
- 229910052750 molybdenum Inorganic materials 0.000 claims description 4
- 239000011733 molybdenum Substances 0.000 claims description 4
- 229910052758 niobium Inorganic materials 0.000 claims description 4
- GUCVJGMIXFAOAE-UHFFFAOYSA-N niobium atom Chemical compound [Nb] GUCVJGMIXFAOAE-UHFFFAOYSA-N 0.000 claims description 4
- 229910052719 titanium Inorganic materials 0.000 claims description 4
- 239000010936 titanium Substances 0.000 claims description 4
- 229910052720 vanadium Inorganic materials 0.000 claims description 4
- GPPXJZIENCGNKB-UHFFFAOYSA-N vanadium Chemical compound [V]#[V] GPPXJZIENCGNKB-UHFFFAOYSA-N 0.000 claims description 4
- HGPXWXLYXNVULB-UHFFFAOYSA-M lithium stearate Chemical compound [Li+].CCCCCCCCCCCCCCCCCC([O-])=O HGPXWXLYXNVULB-UHFFFAOYSA-M 0.000 claims description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 3
- 238000005245 sintering Methods 0.000 description 13
- 239000003795 chemical substances by application Substances 0.000 description 8
- RKISUIUJZGSLEV-UHFFFAOYSA-N n-[2-(octadecanoylamino)ethyl]octadecanamide Chemical compound CCCCCCCCCCCCCCCCCC(=O)NCCNC(=O)CCCCCCCCCCCCCCCCC RKISUIUJZGSLEV-UHFFFAOYSA-N 0.000 description 8
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 7
- 229910052751 metal Inorganic materials 0.000 description 6
- 239000002184 metal Substances 0.000 description 6
- 239000002245 particle Substances 0.000 description 6
- 239000000654 additive Substances 0.000 description 5
- QIQXTHQIDYTFRH-UHFFFAOYSA-N octadecanoic acid Chemical compound CCCCCCCCCCCCCCCCCC(O)=O QIQXTHQIDYTFRH-UHFFFAOYSA-N 0.000 description 5
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 4
- 235000014113 dietary fatty acids Nutrition 0.000 description 4
- 239000000194 fatty acid Substances 0.000 description 4
- 229930195729 fatty acid Natural products 0.000 description 4
- 150000004665 fatty acids Chemical class 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 238000002156 mixing Methods 0.000 description 3
- 229910052814 silicon oxide Inorganic materials 0.000 description 3
- XOOUIPVCVHRTMJ-UHFFFAOYSA-L zinc stearate Chemical class [Zn+2].CCCCCCCCCCCCCCCCCC([O-])=O.CCCCCCCCCCCCCCCCCC([O-])=O XOOUIPVCVHRTMJ-UHFFFAOYSA-L 0.000 description 3
- 229910002012 Aerosil® Inorganic materials 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- 102000005717 Myeloma Proteins Human genes 0.000 description 2
- 108010045503 Myeloma Proteins Proteins 0.000 description 2
- 235000021355 Stearic acid Nutrition 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 125000004432 carbon atom Chemical group C* 0.000 description 2
- 229910052744 lithium Inorganic materials 0.000 description 2
- 238000003754 machining Methods 0.000 description 2
- OQCDKBAXFALNLD-UHFFFAOYSA-N octadecanoic acid Natural products CCCCCCCC(C)CCCCCCCCC(O)=O OQCDKBAXFALNLD-UHFFFAOYSA-N 0.000 description 2
- 239000002904 solvent Substances 0.000 description 2
- 239000010421 standard material Substances 0.000 description 2
- 239000008117 stearic acid Substances 0.000 description 2
- WRIDQFICGBMAFQ-UHFFFAOYSA-N (E)-8-Octadecenoic acid Natural products CCCCCCCCCC=CCCCCCCC(O)=O WRIDQFICGBMAFQ-UHFFFAOYSA-N 0.000 description 1
- LQJBNNIYVWPHFW-UHFFFAOYSA-N 20:1omega9c fatty acid Natural products CCCCCCCCCCC=CCCCCCCCC(O)=O LQJBNNIYVWPHFW-UHFFFAOYSA-N 0.000 description 1
- QSBYPNXLFMSGKH-UHFFFAOYSA-N 9-Heptadecensaeure Natural products CCCCCCCC=CCCCCCCCC(O)=O QSBYPNXLFMSGKH-UHFFFAOYSA-N 0.000 description 1
- UFHFLCQGNIYNRP-UHFFFAOYSA-N Hydrogen Chemical compound [H][H] UFHFLCQGNIYNRP-UHFFFAOYSA-N 0.000 description 1
- 239000005642 Oleic acid Substances 0.000 description 1
- ZQPPMHVWECSIRJ-UHFFFAOYSA-N Oleic acid Natural products CCCCCCCCC=CCCCCCCCC(O)=O ZQPPMHVWECSIRJ-UHFFFAOYSA-N 0.000 description 1
- 239000004952 Polyamide Substances 0.000 description 1
- 125000001931 aliphatic group Chemical group 0.000 description 1
- 229910052783 alkali metal Inorganic materials 0.000 description 1
- -1 alkali metal stearates Chemical class 0.000 description 1
- 229910052784 alkaline earth metal Inorganic materials 0.000 description 1
- 150000001342 alkaline earth metals Chemical class 0.000 description 1
- 125000003118 aryl group Chemical group 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 125000002915 carbonyl group Chemical group [*:2]C([*:1])=O 0.000 description 1
- 238000001816 cooling Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005265 energy consumption Methods 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 238000001704 evaporation Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 239000011874 heated mixture Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- QXJSBBXBKPUZAA-UHFFFAOYSA-N isooleic acid Natural products CCCCCCCC=CCCCCCCCCC(O)=O QXJSBBXBKPUZAA-UHFFFAOYSA-N 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 238000010310 metallurgical process Methods 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000002105 nanoparticle Substances 0.000 description 1
- ZQPPMHVWECSIRJ-KTKRTIGZSA-N oleic acid Chemical compound CCCCCCCC\C=C/CCCCCCCC(O)=O ZQPPMHVWECSIRJ-KTKRTIGZSA-N 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 125000004430 oxygen atom Chemical group O* 0.000 description 1
- 239000011236 particulate material Substances 0.000 description 1
- 229920002647 polyamide Polymers 0.000 description 1
- 238000003825 pressing Methods 0.000 description 1
- 125000002924 primary amino group Chemical group [H]N([H])* 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 235000012239 silicon dioxide Nutrition 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000001993 wax Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
- C10M161/00—Lubricating compositions characterised by the additive being a mixture of a macromolecular compound and a non-macromolecular compound, each of these compounds being essential
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
- C10M141/00—Lubricating compositions characterised by the additive being a mixture of two or more compounds covered by more than one of the main groups C10M125/00 - C10M139/00, each of these compounds being essential
- C10M141/06—Lubricating compositions characterised by the additive being a mixture of two or more compounds covered by more than one of the main groups C10M125/00 - C10M139/00, each of these compounds being essential at least one of them being an organic nitrogen-containing compound
-
- C—CHEMISTRY; METALLURGY
- C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
- C22C—ALLOYS
- C22C33/00—Making ferrous alloys
- C22C33/02—Making ferrous alloys by powder metallurgy
- C22C33/0257—Making ferrous alloys by powder metallurgy characterised by the range of the alloying elements
- C22C33/0278—Making ferrous alloys by powder metallurgy characterised by the range of the alloying elements with at least one alloying element having a minimum content above 5%
- C22C33/0285—Making ferrous alloys by powder metallurgy characterised by the range of the alloying elements with at least one alloying element having a minimum content above 5% with Cr, Co, or Ni having a minimum content higher than 5%
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F3/00—Manufacture of workpieces or articles from metallic powder characterised by the manner of compacting or sintering; Apparatus specially adapted therefor ; Presses and furnaces
- B22F3/12—Both compacting and sintering
- B22F3/14—Both compacting and sintering simultaneously
- B22F2003/145—Both compacting and sintering simultaneously by warm compacting, below debindering temperature
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F9/00—Making metallic powder or suspensions thereof
- B22F9/02—Making metallic powder or suspensions thereof using physical processes
- B22F9/06—Making metallic powder or suspensions thereof using physical processes starting from liquid material
- B22F9/08—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying
- B22F9/082—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying atomising using a fluid
- B22F2009/0824—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying atomising using a fluid with a specific atomising fluid
- B22F2009/0828—Making metallic powder or suspensions thereof using physical processes starting from liquid material by casting, e.g. through sieves or in water, by atomising or spraying atomising using a fluid with a specific atomising fluid with water
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22F—WORKING METALLIC POWDER; MANUFACTURE OF ARTICLES FROM METALLIC POWDER; MAKING METALLIC POWDER; APPARATUS OR DEVICES SPECIALLY ADAPTED FOR METALLIC POWDER
- B22F2998/00—Supplementary information concerning processes or compositions relating to powder metallurgy
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
- C10M2207/00—Organic non-macromolecular hydrocarbon compounds containing hydrogen, carbon and oxygen as ingredients in lubricant compositions
- C10M2207/26—Overbased carboxylic acid salts
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
- C10M2215/00—Organic non-macromolecular compounds containing nitrogen as ingredients in lubricant compositions
- C10M2215/08—Amides
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10M—LUBRICATING COMPOSITIONS; USE OF CHEMICAL SUBSTANCES EITHER ALONE OR AS LUBRICATING INGREDIENTS IN A LUBRICATING COMPOSITION
- C10M2217/00—Organic macromolecular compounds containing nitrogen as ingredients in lubricant compositions
- C10M2217/04—Macromolecular compounds from nitrogen-containing monomers obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
- C10M2217/044—Polyamides
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10N—INDEXING SCHEME ASSOCIATED WITH SUBCLASS C10M RELATING TO LUBRICATING COMPOSITIONS
- C10N2040/00—Specified use or application for which the lubricating composition is intended
- C10N2040/20—Metal working
- C10N2040/244—Metal working of specific metals
- C10N2040/247—Stainless steel
Abstract
The invention concerns a composition for warm compaction comprising a composition comprising a water-atomised standard stainless steel powder including, in addition to iron and 10-30% by weight of chromium, optional alloying elements and inevitable impurities, 0.8%-2.0% by weight of a warm compaction lubricant.
Description
COMPOSITION AND PROCESS FOR WARM COMPACTION OF STAINLESS STEEL POWDERS. . Field of invention
The present invention concerns steel powder ] compositions as well as the compacted and sintered bodies obtained thereof. Specifically the invention concerns stainless steel powder compositions for warm compaction.
Since the start of the industrial use of powder metallurgical processes i.e. the pressing and sintering of metal powders, great efforts have been made in order to enhance the mechanical properties of P/M-components and to improve the tolerances of the finished parts in order to expand the market and achieve the lowest total cost.
Recently much attention has been paid to warm com- paction as a promising way of improving the properties of
P/M components. The warm compaction process gives the opportunity to increase the density level, i.e. decrease the porosity level in finished parts. The warm compaction process is applicable to most powder/material systems.
Normally the warm compaction process leads to higher strength and better dimensional tolerances. A possibility of green machining, i.e. machining in the “as-pressed” state, is also obtained by this process.
Warm compaction is considered to be defined as compaction of a particulate material mostly consisting of metal powder above approximately 100°C up to approxi- mately 150°C according to the currently available powder technologies such as Densmix™, Ancorbond™ or Flow-Met™.
A detailed description of the warm compaction pro- cess is described in e.g. a paper presented at PM TEC 96
World Congress, Washington, June 1996, which is hereby incorporated by reference. Specific types of lubricants used for warm compaction of iron powders are disclosed in e.g. the US patents 5 154 881 (Rutz) and 5 744 433 (Storstrom) .
Until recently it has been observed that the general advantages with warm compaction have been insignificant as only minor differences in e.g. density and green 3 strength have been demonstrated in the case of stainless steel powders. Major problems encountered when warm compacting stainless steel powders are the high ejection forces and the high internal friction during compaction.
However, as disclosed in the US patent 6 365 095 (Bergkvist), it was recently found that stainless steel powders may be subjected to warm compaction with good results provided that the stainless steel powder is distinguished by very low oxygen, carbon and silicon levels. The widely used standard qualities having higher levels of these elements could however not be successfully warm compacted i.e. the properties of the warm compacts were not significantly better than the green density of a corresponding body compacted at ambient temperature.
It has now unexpectedly been found that also standard stainless steel powders can be compacted at elevated temperatures with good results. In comparison with the stainless steel powders disclosed in the above
US patent the standard stainless powders are generally characterised in a higher amount of oxygen, carbon and silicon. These powders are also easier to produce and accordingly cheaper. According to the present invention it has thus, contrary to the teaching in the US patent, been found that these standard powders can be compacted to high green densities without the use of excessively high compaction pressures. The high green density is valuable when the product is subsequently sintered as it is not necessary to use high sintering temperatures and accompanying high energy consumption in order to get a high sintered density which is normally necessary in
: order to get good mechanical properties. Additionally high sintering temperatures induce strains in the material which in turn gives poor dimensional stability.
In brief the process of preparing high density, warm } compacted bodies of a water atomised standard stainless steel powder according to the present invention is based on the discovery that specific amounts of lubricants have to be used in the stainless steel powder composition which is subjected to the compaction at elevated temperature. Minor amounts of selected additives included in the composition contribute to the unexpected finding that standard stainless steels can be successfully compacted.
Type of powder
Preferably the powders subjected to warm compaction are pre-alloyed, water atomised powders which include, by percent of weight, 10-30% of chromium. These powders are stainless steel powders of standard type and include at least 0.5% by weight of silicon. Normally the silicon content is between 0.7 and 1.0% by weight of the steel powder. The stainless steel powder may also include other elements such as, molybdenum, nickel, manganese, niobium, titanium, vanadium. The amounts of these elements may be 0-5% of molybdenum, 0-22% of nickel, 0-1.5% of manganese, 0-2% of niobium, 0-2% of titanium, 0-2% of vanadium, and at most 1% of inevitable impurities and most preferably 10-20% of chromium, 0-3% of molybdenum, 0.1-0.4% of manganese, 0-0.5% of niobium, 0-0.5% of titanium, 0-0.5% of vanadium and essentially no nickel or alternatively 5-15% of nickel, the balance being iron and unavoidable impurities (normally less than 1% by weight).
Furthermore, the average particle size of the steel powder should preferably be above about 30 pm and a suitable interval is between 30 and 70 pm.
Examples of stainless steel powders which are suitably used according to the present invention are 316
L, 409 Nb,409 L, 410 L, 434 L. The standard steel powders used according to the present invention generally include more than 0.5% by weight of Si and normally the Si content is 0.7-1.0% by weight. This feature distinguishes standard stainless powders from the stainless powders used for the warm compaction according to the US patent 6 365 095 (Bergkvist) mentioned above.
Amount of lubricant
The amount of lubricant in the composition to be compacted is an important factor for the possibility to get a satisfactory result. It has thus been found that the total amount of lubricant should be above 0.8% by weight, preferably at least 1.0% by weight and most preferably at least 1.2% by weight of the total powder composition. As increasing amounts of lubricant decrease the final green density due to the fact that the lubricants normally have much lower density than the metal powder, lubricant amounts above 2.0% by weight are less important. In practice it is believed that the upper limit should be less than 1.8% by weight. A minor amount, such as at least 0.05 and at most 0.4% by weight of the lubricant should preferably be a compound having high oxygen affinity, which promotes the sintering activity.
Type of lubricant
The lubricant may be of any type as long as it is com- patible with the warm compaction process. Examples of such lubricants are disclosed in e.g. the US patents 5 154 881 (Rutz) and 5 744 433 (Storstrom), which are referred to above and which are hereby incorporated by reference. The lubricants may also be e.g. metal stearates, such as lithium stearate, zinc stearate;
paraffins; waxes; natural and synthetic fat derivatives and polyamides. Preliminary results have also shown that lubricants conventionally used for cold compaction, such as EBS, may be used for warm compaction of the standard 5 steel powders according to the present invention although ) the flow properties of such powder compositions are inferior.
So far however the most promising results have been obtained by using a type of lubricants disclosed in the copending patent application SE02/00762 PCT. These type of lubricants include an amide component which can be represented by the following formula
D-Cpa-B-A-B-Cyp-D wherein
D is -H, COR, CNHR, wherein R is a straight or branched aliphatic or aromatic group including 2-21 C atoms
C is the group -NH (CH), CO-
B is amino or carbonyl
A is alkylen having 4-16 C atoms optionally including up to 4 O atoms ma and mb which may be the same of different is an integer 1-10 n is an integer 5-11.
Examples of preferred such amides are:
CH3 (CH) 16CO-[HN (CH) 11COJ2-HN (CH) 1 2NH-[OC (CH3) 11NH]>-
OC (CH2) 16CH3
CH3(CHp)qgCO-[HN(CHp)11CO]2—HN (CHp) 12NH-[OC (CH) 11 NH]3-
OC (CH2) 16CH3
CH3 (CHp) 1 6CO-[HN (CH) 11CO]3-HN (CHp) 1 oNH-[OC (CHD) 11 NH]3-
OCCHp) 16CH3
CH3 (CHp) 1 gCO-[HN (CHp) 11CO]3-HN (CH) 1oNH-[OC (CH2) 1 1NH]4~
OC (CH) 1 6CH3
CH3 (CHp) 1 gCO-[HN (CHy) 11CO}4-HN (CH) 12NH~[OC (CH) 11NH]4~-
OC (CHp) 1¢CH3
CH3(CHp)16CO-[HN(CHp) 11C0]4-HN(CHp) 12NH-[OC (CHp) 11NH]5-
OC (CH») 1 6CH3 :
CH3 (CH2) 1 6CO-[HN (CH) 11CO]5-HN (CH2) 12NH-[OC (CH) 11NH]5-
OC(CHp) 16CH3, :
As previously mentioned the lubricant should preferably also include a compound having high affinity for oxygen. Examples of such high affinity compounds are alkali metal stearates. Other examples are stearates of alkaline earth metals. The presently most preferred compound being lithium stearate.
Selected additives
According to a preferred embodiment of the invention minor amounts of selected additives may be included in the composition before the powder composition is subjected to warm compaction. These additives include fatty acids and flow enhancing agents.
The fatty acid may be selected from the group consisting of stearic acid and oleic acid. The amounts of the fatty acid in the composition according to the invention may vary between 0.005 and 0.5, preferably between 0.010 and 0.16 and most preferably between 0.015 and 0.10% of the lubricant composition. The fatty acid has an beneficial effect on the apparent density. : The flow agent may be a material of the type described in the US patent 5 782 954 (Luk). This material : is comprised of nanoparticles of various metals and their oxides such as silicon oxide. Typically, the metal and metal oxide powders have average particle sizes below about 500 nanometers. The silicon oxide flow agents are
; preferably blended with the iron-based powders in an amount of from about 0.005 to about 2 percent by weight of the resultant powder composition. The preferred silicon oxide flow agents are powders or particles of silicon dioxide having an average particle size below about 40 nanometers. An example of a suitable flow agent is Aerosil.
Warm compaction
The stainless steel powder including the lubricant and optional additives is subsequently compacted at an elevated temperature. The warm compaction may be performed with a preheated powder, a preheated die or both. The powder could e.g. be preheated to a temperature above 60°C preferably above 90°C. A suitable interval for the warm compaction is between 100°C and 200°C, and preferably the compaction could be performed at a temperature less than about 150°C. The compaction is performed in standard compaction equipment with compaction pressures preferably between about 400 and 2000 MPa, preferably between about 500 and 1000 MPa.
The powder mixes used for the warm compaction can be prepared mainly in two ways. An alternative 1s to prepare the powder mix by carefully blending the steel powder, the lubricant (s) in the form of solid particles and a flow agent to a homogenous mix. An other alternative is to make the lubricants stick (adhere) to the stainless steel powder particles. This can be done by heating a mixture including the steel powder and the lubricant (s) to a temperature above the melting point of the lubricant (s), mixing the heated mixture and cooling the : obtained mixture before the flow agent is added. It can also be done by dissolving the lubricant(s) in a solvent, mixing the obtained solution with the steel powder, evaporating the solvent in order to obtain a dry mixture to which the flow agent is subsequently added.
Sintering
The obtained green bodies are then sintered in the same way as the standard materials, i.e. at temperatures between 1100°C and 1400° C, the most pronounced advantages being obtained when the sintering is performed ’ between 1250 and 1325°C. A lower sintering temperature may be used in order to reach a given sintered density by } using warm compaction instead of compaction at ambient temperature. Furthermore the sintering is preferably carried out in standard non oxidative atmosphere for periods between 15 and 90, preferably between 20 and 60 minutes. The high densities according to the invention are obtained without the need of recompacting, resinte- ring and/or sintering in vacuum or reduced atmosphere.
The invention is illustrated by the following non limiting examples.
Example 1
This experiment was carried out with a standard materials 434 LHC, 409 Nb, 316 LHD och 410 LHC which are all available from Hogands, Belgium and have the compositions indicated in table 1.
Table 1 bor lew lwo esi [wn joe bso ere 4301 Peo lor ho 0.76 fo.16 [0 Jo.016 Jo.22 far 409 wo [11.3 or po ho Jor fo.sfo.or Jos far 3161 [16.9 [12.8 ps os for lo lo.o2 o.36 far a0r his Joo fo fos Jor lo fo.01 fo.2a [rar . Compaction was made on samples of 50 g of these stainless steel powders at 600 and 800 MPa. The warm compaction was performed with a powder temperature and a die temperature of 110°C. The amounts of lubricants are disclosed in the following table 2, wherein CC (cold compaction which is the conventional type of compaction)
indicates that the compaction was performed at room ' temperature (ambient temperature) and WC indicates warm compaction.
Table 2
Ce EE ETE
Sample Powder lubricant composition [compaction 34, laser Joer | cc 34 lan oer Bb | we 409 loo wo 2 la | we
S160 Pren p2 Ja | we ron po Ja | we e100 lon pa bo | we *not within the scope of the invention
The following lubricants and lubricant compositions were used in the different samples: 10 a Ethylene bisstearamide (EBS) b Advawax c EBS +0.3% Li stearate d 1.0% amide oligomer (according to the patent publication WO 02083345) + 0.2% Li stearate, 0.05% stearic acid, 0.1% Aerosil
The different compositions were prepared as follows:
Compositions including EBS and EBS + Li stearate, respectively, were admixed before the compaction operation. The compositions including Advawax were prepared according to the method disclosed in the US patent 5 429 792 and the compositions including the amide ) oligomer were prepared according to the method disclosed in the patent publication WO 02083346.
The following Table 3 discloses the green densities obtained when the samples were compacted at 600 MPa and 800 MPa, respectively.
Table 3
Er
Sample (g/cm) at 600 MPa (g/cm®) at 800 MPa 6.76 6.61 * problems during compaction, no sintering possible. ** gomewhat reduced flow
The green parts were sintered at 1160°C in hydrogen atmosphere for 45 min, after which the sintered density was measured (Table 4).
Table 4 ria at 600 MPa (g/cm®) at 800 MPa
S160 | 690 | 719 ) The results disclosed in table 5 were obtained when the sintering was performed at 1250°C.
WO ¢3/106077 PCT/SE03/01001
Table 5 (g/cm®) at 600 MPa (g/cm?) at 800 MPa : 7.22
The following table 6 discloses the tensile properties after sintering at 1250°C.
Table 6
Ultimate Ultimate
ELE ee pe strength MPa|strength MPa (%) (%)
Sample [600 MPa 800 MPa 600 MPa 800 MPa
The following table 7 discloses the impact energy after sintering at 1250°C.
Table 7
Cr
Sample [600 MPa 800 MPa
Claims (9)
1. A composition for warm compaction of a water atomised stainless steel powder including iron and 10 - 30% by weight of chromium, optional alloying elements and } inevitable impurities, and a lubricant, characterised in that the steel powder is a standard steel powder and that the lubricant is present in an amount of 0.8% —- 2.0% by weight.
2. Composition according to claim 1 wherein the steel powder includes at least 0.5% by weight of silicon.
3. Composition according to claim 2 wherein the steel powder includes 0.7 -1.0% by weight of silicon.
4. Composition according to any one of the preceding claims wherein the steel powder includes one or more element selected from the group consisting of molybdenum, nickel, manganese, niobium, titanium, vanadium and at most 1.0% by weight of inevitable impurities.
5. Composition according to any one of the preceding claims wherein the lubricant is a warm compaction lubricant.
6. Composition according to any one of the claims 1- 5 wherein the lubricant is combined with up to 0.4% by weight of a high oxygen affinity compound.
7. Composition according to claim 6 wherein the lubricant includes between about 0.05 and 0.3% by weight of a high oxygen affinity compound.
8. Composition according to claim 6 or 7 wherein the high oxygen affinity compound is lithium stearate.
9. Composition according to any one of the preceding . claims, wherein the lubricant in addition to the optional } high oxygen affinity compound essentially consists of an amide oligomer lubricant having the formula D-Cpa=B-A-B-Cpp~D wherein
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
SE0201825A SE0201825D0 (en) | 2002-06-14 | 2002-06-14 | Hot compaction or steel powders |
Publications (1)
Publication Number | Publication Date |
---|---|
ZA200409738B true ZA200409738B (en) | 2006-06-28 |
Family
ID=20288191
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
ZA200409738A ZA200409738B (en) | 2002-06-14 | 2004-12-01 | Composition and process for warm compaction of stainless steel powders |
Country Status (18)
Country | Link |
---|---|
US (1) | US6712873B2 (en) |
EP (1) | EP1513639B1 (en) |
JP (1) | JP4863618B2 (en) |
KR (1) | KR20100126806A (en) |
CN (1) | CN1299859C (en) |
AT (1) | ATE483540T1 (en) |
AU (1) | AU2003239021B2 (en) |
BR (1) | BR0311794A (en) |
CA (1) | CA2489489C (en) |
DE (1) | DE60334454D1 (en) |
DK (1) | DK1513639T3 (en) |
ES (1) | ES2353845T3 (en) |
MX (1) | MXPA04012570A (en) |
RU (1) | RU2294815C2 (en) |
SE (1) | SE0201825D0 (en) |
TW (1) | TW575472B (en) |
WO (1) | WO2003106077A1 (en) |
ZA (1) | ZA200409738B (en) |
Families Citing this family (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP2004148414A (en) * | 2002-10-28 | 2004-05-27 | Seiko Epson Corp | Abrasive and production method for abrasive and production device used for the same |
US20040151611A1 (en) * | 2003-01-30 | 2004-08-05 | Kline Kerry J. | Method for producing powder metal tooling, mold cavity member |
US7473295B2 (en) * | 2004-07-02 | 2009-01-06 | Höganäs Ab | Stainless steel powder |
SE0401707D0 (en) * | 2004-07-02 | 2004-07-02 | Hoeganaes Ab | Stainless steel powder |
CN1332055C (en) * | 2005-04-14 | 2007-08-15 | 华南理工大学 | Stainless steel powder composite material and its warm-pressing method |
CN100450672C (en) * | 2005-10-28 | 2009-01-14 | 合肥波林新材料有限公司 | Warm processing powdered iron, and preparation method |
US8992659B2 (en) * | 2009-09-08 | 2015-03-31 | Hoganas Ab (Publ) | Metal powder composition |
EP2511031A1 (en) * | 2011-04-12 | 2012-10-17 | Höganäs Ab (publ) | A powder metallurgical composition and sintered component |
CN104084577A (en) * | 2014-07-18 | 2014-10-08 | 常熟市迅达粉末冶金有限公司 | Powder metallurgy material |
CN104096834A (en) * | 2014-07-18 | 2014-10-15 | 常熟市迅达粉末冶金有限公司 | Additive for powder metallurgy |
CN105648300B (en) * | 2014-11-12 | 2017-09-22 | 东睦新材料集团股份有限公司 | For the method for the related stainless steel sintered component of additive and its manufacture for improving stainless steel sintered density |
CN104858422B (en) * | 2015-05-22 | 2017-05-31 | 东莞劲胜精密组件股份有限公司 | A kind of stainless steel composite powder for 3D printing and preparation method thereof |
CN105345009A (en) * | 2015-11-19 | 2016-02-24 | 苏州紫光伟业激光科技有限公司 | Method for manufacturing part through stainless steel powder |
CN106541127B (en) * | 2016-11-25 | 2018-10-26 | 西华大学 | Powder of stainless steel plank and preparation method thereof |
CN106541126A (en) * | 2016-11-25 | 2017-03-29 | 西华大学 | A kind of preparation method of high density powder of stainless steel |
KR20210107289A (en) | 2020-02-24 | 2021-09-01 | 현대자동차주식회사 | Stainless steel powder, powder composition for powder metallurgy containing the same and method of manufacturing the same |
RU2750720C1 (en) * | 2020-04-18 | 2021-07-01 | Федеральное государственное бюджетное образовательное учреждение высшего образования "Юго-Западный государственный университет" (ЮЗГУ) | Method of obtaining a sintered product from powder corrosive steel |
Family Cites Families (10)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
GB779949A (en) * | 1954-11-30 | 1957-07-24 | Birmingham Small Arms Co Ltd | Improvements in or relating to the production of powder metal compacts |
US5154881A (en) | 1992-02-14 | 1992-10-13 | Hoeganaes Corporation | Method of making a sintered metal component |
FR2707191B1 (en) | 1993-07-06 | 1995-09-01 | Valinox | Metallic powder for making parts by compression and sintering and process for obtaining this powder. |
SE9401922D0 (en) | 1994-06-02 | 1994-06-02 | Hoeganaes Ab | Lubricant for metal powder compositions, metal powder composition containing th lubricant, method for making sintered products using the lubricant, and the use of same |
GB9624999D0 (en) * | 1996-11-30 | 1997-01-15 | Brico Eng | Iron-based powder |
SE511834C2 (en) | 1998-01-13 | 1999-12-06 | Valtubes Sa | Fully dense products made by uniaxial high speed metal powder pressing |
SE9803171D0 (en) | 1998-09-18 | 1998-09-18 | Hoeganaes Ab | Hot compaction or steel powders |
US6140278A (en) | 1998-11-04 | 2000-10-31 | National Research Council Of Canada | Lubricated ferrous powder compositions for cold and warm pressing applications |
SE9903244D0 (en) | 1999-09-10 | 1999-09-10 | Hoeganaes Ab | Lubricant for metal-powder compositions, metal-powder composition cantaining the lubricant, method for making sintered products using the lubricant, and the use of same |
SE0101344D0 (en) | 2001-04-17 | 2001-04-17 | Hoeganaes Ab | Iron powder composition |
-
2002
- 2002-06-14 SE SE0201825A patent/SE0201825D0/en unknown
- 2002-07-30 US US10/207,225 patent/US6712873B2/en not_active Expired - Fee Related
- 2002-08-09 TW TW91118019A patent/TW575472B/en not_active IP Right Cessation
-
2003
- 2003-06-13 BR BR0311794-4A patent/BR0311794A/en not_active Application Discontinuation
- 2003-06-13 CA CA2489489A patent/CA2489489C/en not_active Expired - Fee Related
- 2003-06-13 MX MXPA04012570A patent/MXPA04012570A/en active IP Right Grant
- 2003-06-13 JP JP2004512955A patent/JP4863618B2/en not_active Expired - Fee Related
- 2003-06-13 KR KR1020107022770A patent/KR20100126806A/en not_active Application Discontinuation
- 2003-06-13 AT AT03733739T patent/ATE483540T1/en not_active IP Right Cessation
- 2003-06-13 RU RU2005100785/02A patent/RU2294815C2/en not_active IP Right Cessation
- 2003-06-13 DE DE60334454T patent/DE60334454D1/en not_active Expired - Lifetime
- 2003-06-13 WO PCT/SE2003/001001 patent/WO2003106077A1/en active Application Filing
- 2003-06-13 ES ES03733739T patent/ES2353845T3/en not_active Expired - Lifetime
- 2003-06-13 EP EP03733739A patent/EP1513639B1/en not_active Expired - Lifetime
- 2003-06-13 CN CNB038138085A patent/CN1299859C/en not_active Expired - Fee Related
- 2003-06-13 DK DK03733739.1T patent/DK1513639T3/en active
- 2003-06-13 AU AU2003239021A patent/AU2003239021B2/en not_active Ceased
-
2004
- 2004-12-01 ZA ZA200409738A patent/ZA200409738B/en unknown
Also Published As
Publication number | Publication date |
---|---|
CN1662328A (en) | 2005-08-31 |
CN1299859C (en) | 2007-02-14 |
US6712873B2 (en) | 2004-03-30 |
JP2005530035A (en) | 2005-10-06 |
KR20100126806A (en) | 2010-12-02 |
EP1513639B1 (en) | 2010-10-06 |
ATE483540T1 (en) | 2010-10-15 |
DE60334454D1 (en) | 2010-11-18 |
BR0311794A (en) | 2005-03-15 |
DK1513639T3 (en) | 2011-01-31 |
MXPA04012570A (en) | 2005-04-19 |
AU2003239021B2 (en) | 2006-09-07 |
JP4863618B2 (en) | 2012-01-25 |
WO2003106077A1 (en) | 2003-12-24 |
EP1513639A1 (en) | 2005-03-16 |
CA2489489C (en) | 2011-04-26 |
ES2353845T3 (en) | 2011-03-07 |
US20030230165A1 (en) | 2003-12-18 |
RU2294815C2 (en) | 2007-03-10 |
TW575472B (en) | 2004-02-11 |
SE0201825D0 (en) | 2002-06-14 |
RU2005100785A (en) | 2005-09-10 |
AU2003239021A1 (en) | 2003-12-31 |
CA2489489A1 (en) | 2003-12-24 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
ZA200409738B (en) | Composition and process for warm compaction of stainless steel powders | |
EP0639232B1 (en) | Iron-based powder compositions containing novel binder/lubricants | |
EP2370220B1 (en) | Lubricant for powder metallurgical compositions | |
US20100186551A1 (en) | Coarse Iron or Iron-Based Powder Composition Containing Specific Lubricant | |
EP1735121A2 (en) | Powder metallurgical compositions and methods for making the same | |
ZA200101630B (en) | Warm compaction of steel powders. | |
US6511945B1 (en) | Lubricant powder for powder metallurgy | |
EP1513638B1 (en) | Metal powder composition including a bonding lubricant and a bonding lubricant comprising glyceryl stearate. | |
CA2443481C (en) | Iron powder composition including an amide type lubricant and a method to prepare it | |
EP1387730B1 (en) | Iron powder composition including an amide type lubricant and a method to prepare it | |
KR100865929B1 (en) | Improved Powder Metallurgy Lubricant Compositions and Methods for Using the Same | |
KR20050016529A (en) | Composition and process for warm compaction of stainless steel powders | |
KR100977652B1 (en) | Metal powder composition including a bonding lubricant and a bonding lubricant comprising glyceryl stearate |